This relates generally to electronic devices and, more particularly, to electronic devices with displays and associated backlight structures.
Electronic devices such as computers and cellular telephones may have displays. Some displays such as plasma displays and light-emitting diode displays have arrays of display pixels that generate light. In displays of this type, backlighting is not necessary, because the display pixels themselves are illuminated. Other displays, such as liquid crystal displays, contain passive display pixels. The pixels in a liquid crystal display can alter the amount of light that is transmitted through the display to display information for a user, but do not produce light. As a result, it is often desirable to provide backlight for a liquid crystal display.
In a typical backlight structure for a display such as a liquid crystal display, a light guide plate is used to distribute backlight generated by a light source such as a light-emitting diode light source. Optical films such as a diffuser layer and brightness enhancing film may be placed on top of the light guide plate. A reflector may be formed under the light guide plate to improve backlight efficiency.
Conventional backlight arrangements are often not as compact as desired. The inclusion of optical films, provisions for registering the positions of the optical films within a device, the size and shape of the conventional light guide plates and light source, and other conventional backlight design features raise challenges when attempting to make backlights less bulky and more efficient.
It would therefore be desirable to be able to provide electronic devices with improved displays and backlights.